Il A heavy ball with a weicht of 100 N (m 10.2 kg) is hung. from the ceiling of a lecture hall on a 4.5-m-long rope. The ball. is pulled to one side and released to swing as a pendulum, reach-. ing a speed of 5.5 m/s as it passes throuoh the lowest point.
Inventions. The huochong gun was invented in China during the Ming dynasty. It was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.t was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.
This article is about the history of the Ming dynasty. For the historical text and source book, see History of Ming. The Ming dynasty (January 23, 1368 â April 25, 1644), officially the Great Ming or Empire of the Great Ming, founded by the peasant rebel leader Zhu Yuanzhang, known as the Hongwu Emperor, was an imperial dynasty of China.